DE112018000276B4 - Gas heat pump and control method therefor - Google Patents

Abstract

A method for controlling a gas heat pump having a compressor for compressing refrigerant and a gas engine for driving the compressor, the gas engine comprising: an engine combustion unit having a plurality of combustion chambers and a spark plug arranged at each of the engine combustion chambers for combusting a mixture of air and fuel, the method comprising:determining a refrigerant charge based on a cooling or heating mode or a temperature setting (S412);determining an output amount of the gas engine based on the determined refrigerant load (S412);setting a target ignition energy amount (S413) that is of the spark plug is required based on the output amount;igniting the spark plug in each combustion chamber (S420);measuring a magnitude of a current that changes based on a voltage applied to the spark plug and based on a dwell time of the spark plug in real time for each ignition time ;comparing an actual amount of output energy generated by the ignition with the set target amount of ignition energy (S431); andchanging an amount of energy required to ignite the fuel when the output energy amount and the target ignition energy amount are not equal (S432); anddetermining whether the operating condition has changed when the output energy amount is equal to the target ignition energy amount (S440),wherein if the operating condition has changed, setting the target ignition energy amount includes setting a new refrigerant charge and a new target ignition energy amount ( S412, S413).

Description

technical field

The present disclosure relates to gas heat pumps and control methods therefor, in which an amount of energy generated by a spark plug is calculated and then an ignition state varies based on the calculated amount.

State of the art

A refrigeration cycle generally refers to a cycle in which the cycle of a refrigerant is used to add or absorb heat to or from a destination. A compressor, a condenser, an expansion valve, and an evaporator are used to perform this refrigeration cycle. These components are connected to each other via refrigerant lines. Due to a phase change in the refrigerant, the condenser gives off heat to the environment and the evaporator absorbs the heat from the environment.

In this regard, the condenser and the evaporator may be configured to perform heat exchange between the refrigerant and air or other fluids. Therefore, the condenser and the evaporator can be called a heat exchanger, which can be divided into the condenser and the evaporator based on the state of the refrigerant before and after the heat exchange.

An apparatus or system for heating or cooling indoor air using such a refrigeration cycle is referred to as an air conditioner. To heat the room by the air conditioner, the refrigerant gives off heat to the room air. Therefore, in this case, an indoor unit can be referred to as a condenser and an outdoor unit as an evaporator. Conversely, the refrigerant absorbs the heat from the room air to cool the room through the air conditioner. Therefore, in this case, the indoor unit can be referred to as an evaporator and the outdoor unit as a condenser.

Unlike houses, large capacity compressors are required for industrial purposes and in large buildings for air conditioning. That is, a gas heat pump system that uses a gas engine instead of an electric motor to drive a compressor for compressing a large amount of refrigerant into a high-temperature and high-pressure gas is widely used.

This gas heat pump system generates the energy to drive the compressor using an engine that burns the gas to perform the refrigeration cycle.

In general, the gas heat pump system is configured for heating or cooling by operating the compressor using a driving force of a gas engine. This system consists of a refrigerant cycle system 100 and an engine cooling water cycle system 200, as in FIG 1 shown.

The refrigerant cycle system defines a refrigeration cycle or a heat pump cycle for cooling or heating the interior, and includes a compressor driven by a gas engine 500 for compressing the refrigerant, a four-way valve 15, an outdoor unit heat exchanger 16, a heating expansion valve 17, an indoor unit expansion valve 18, an indoor unit heat exchanger 19, and an accumulator 13.

The engine cooling water circulation system 200 circulates engine cooling water to cool the gas engine 500, and includes an engine cooling water three-way valve 21, a radiator 22, an engine cooling water circulating pump 23, an exhaust gas heat exchanger 24 and the like.

Further, an auxiliary heat exchanger 25 is installed between the refrigerant cycle system 100 and the engine cooling water cycle system 200 such that refrigerant is vaporized through heat exchange between refrigerant and engine cooling water.

During the cooling operation of the conventional gas engine-based cooler/heater, the four-way valve 15 is switched as indicated by a solid arrow in FIG 1 is specified. Accordingly, the refrigerant compressed and brought into a high temperature and high pressure state by the compressor 14 driven by the gas engine 500 flows through the four-way valve 15 which is switched to the cooling operation mode, and then is discharged into the outdoor unit heat exchanger 16 which is operated as a Condenser works, condenses and thus gives off the condensation heat to the outside air. The condensed liquid refrigerant is decompressed in the indoor expansion valve 18 and then flows into the indoor heat exchanger 19 functioning as an evaporator in a low temperature and low pressure state and then evaporates therein. In this way, cooling is achieved by capturing the latent heat required for the evaporation process from the room air.

Further, the refrigerant passing through the indoor heat exchanger 19 passes through the battery modulator 13, and then only the gaseous refrigerant is sucked into the compressor, thereby continuously forming the refrigeration cycle.

Further, during the cooling operation, the engine cooling water that has cooled the gas engine 500 is led to the radiator 22 via the engine cooling water three-way valve 21 and gives off heat to the outside air in the radiator 22, and then passes through the exhaust gas heat exchanger 24 through the engine refrigerant circulation pump 23 and then returns to the gas engine 500 back.

However, during the heating operation, the four-way valve 15 is switched, as indicated by the dashed arrow in FIG 1 is specified. Thus, the high-temperature, high-pressure refrigerant compressed by the compressor 14 flows into the indoor unit I and is condensed in the indoor unit heat exchanger 19 functioning as a condenser, so that heating occurs using the condensation heat released into the indoor air. The refrigerant in the condensed liquid state is decompressed to a low temperature and low pressure state while flowing through the heater expansion valve 17 . Then, the refrigerant flows into the outdoor heat exchanger 16 functioning as an evaporator and starts evaporating therein.

Furthermore, the temperature of the outdoor air is usually low during the winter season when the heating operation is performed. Accordingly, in order to lower the evaporating temperature, the power required for the compressor increases, thereby deteriorating the performance of the heat pump cycle. To prevent this situation, part of the engine exhaust heat is recovered and used as a heat source for evaporating the refrigerant. That is, during the heating operation, the engine cooling water that has cooled the gas engine 500 is guided to the auxiliary heat exchanger 25 side via the engine cooling water three-way valve 21, and thus heats the refrigerant flowing into the auxiliary heat exchanger 25 through the outdoor heat exchanger 16 to evaporate the refrigerant.

In this way, the refrigerant vaporized while sequentially passing through the outdoor heat exchanger 16 and the auxiliary heat exchanger 25 passes through the accumulator 13 so that only the gaseous refrigerant is drawn into the compressor 14 . Thus, the heat pump cycle is formed continuously.

The conventional gas heat pump system is in the Korean patent application KR 10 2013 0 093 297 A disclosed.

Further, in the conventional gas heat pump system, the output of the gas engine 500 was adjusted by controlling the voltage applied to a spark plug provided in the gas engine 500. FIG. However, when the output of the gas engine 500 is controlled only by the voltage control, there is a problem that in a compressor speed range and a range that requires high torque based on an operating state of the refrigeration cycle (selection between cooling and heating and temperature selection), no optimal Ignition energy output can be achieved.

From the U.S. 5,213,080 B1 a control device for a gas engine is known which is designed to ignite the gas at a suitable time. From the JP 2008 - 291 721 A an ignition device for a gas engine is known in which the duration of the spark discharge is varied depending on the measured voltage between the electrodes. From the JP 2016 - 113 921 A , JP 2008 - 38 729 A , JP 2001 - 323 863 A and the JP 2007 - 127 369 A other gas engines of gas heat pumps are known.

epiphany

technical purpose

The present disclosure provides a gas heat pump and a control method therefor that can vary the dwell time according to the amount of ignition energy released from a spark plug.

Further, the present disclosure provides a gas heat pump and a control method therefor that can control a magnitude of voltage applied to the spark plug.

Further, the present disclosure provides a gas heat pump and a control method therefor, in which whenever discharge occurs in the spark plug, feedback therefor can be provided.

The technical purposes to be achieved according to the present disclosure are not limited to the above-mentioned technical purposes. Other technical purposes not mentioned can be clearly understood by those skilled in the art to which the present disclosure pertains from the following description.

Technical solutions

In one aspect, to achieve the purpose of the present disclosure, a method for controlling a gas heat pump is disclosed provided with the features of claim 1. In the method, a gas heat pump comprises a gas engine having an engine combustion unit including a plurality of combustion chambers, each chamber being provided with a spark plug, the method including the following steps: establishing a target ignition energy amount based on a refrigerant charge, which is based on a Driving state of the gas heat pump is determined; igniting fuel injected into each combustion chamber; comparing an actual amount of output energy produced by the ignition to the set target amount of ignition energy; and changing an amount of energy required to ignite the fuel when the output amount of energy and the target amount of ignition energy are not equal.

From a second aspect, to achieve the purpose of the present disclosure, a gas heat pump having the features of claim 11 is provided. The gas heat pump includes, among other things: a compressor for compressing refrigerant; a gas engine for driving the compressor, the gas engine including an engine combustion unit having a plurality of combustion chambers; a spark plug arranged at each of the engine combustion chambers, the spark plug applying a surge voltage; and a controller for controlling a voltage and current applied to the spark plug and a discharge time of the spark plug, the controller configured to: determine a refrigerant charge based on an operating state of the gas heat pump; setting a target ignition energy amount based on the refrigerant charge; comparing an actual amount of output energy generated by ignition of the spark plug with the target amount of ignition energy; and changing an amount of energy required to ignite the fuel based on the comparison result.

technical effects

The present disclosure has the following effects.

The present disclosure causes the dwell time to be varied depending on the amount of ignition energy delivered by the spark plug, thus enabling accurate control.

In addition, the present disclosure acts to control the magnitude of the voltage applied to the spark plug.

Further, the present disclosure has the effect of providing feedback on the discharge whenever the discharge occurs in the spark plug and cope with the changes in the heating/cooling and temperature settings immediately.

The effects from the present disclosure are not limited to the effects mentioned above. Other effects not mentioned can be clearly understood by those skilled in the art to which the present disclosure pertains from the following description.

character list

• 1 shows a basic structure of a gas heat pump system.
• 2 12 illustrates a structure of a gas engine according to an embodiment of the present disclosure.
• 3 12 shows a structure of an engine combustor according to an embodiment of the present disclosure.
• 4 12 is a simplified representation of a transformation process of a spark plug according to an embodiment of the present disclosure.
• 5 1 is a simplified representation of a current sensing circuit according to an embodiment of the present disclosure.
• 6 12 is a simplified illustration of an ignition process in the engine combustion chamber based on voltage, according to an embodiment of the present disclosure.
• 7 FIG. 12 is a flow chart depicting a basic algorithm according to an embodiment of the present disclosure.
• 8th 12 is a flow chart depicting an algorithm for operating the engine combustor using an amount of energy according to an embodiment of the present disclosure.

Detailed description

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

While the present disclosure permits various changes and modifications, specific embodiments thereof are shown by way of example with reference to the drawings and will be described in detail below. However, these embodiments are not intended to limit the present disclosure to any particular extent limit the form. Rather, the present disclosure includes all modifications, equivalents, and substitutions consistent with the spirit and scope of the present disclosure as defined in the claims.

It is also understood that when a first element or layer is referred to as being "on" or "beneath" a second element or layer, the first element may be disposed directly on or below the second element, or indirectly on or disposed below the second element with a third element or layer disposed between the first and second element or layer.

It is understood that although the terms "first", "second", "third" etc. may be used herein to describe various elements, components, regions, layers and/or portions of these elements, components, regions, layers and/or Sections are not intended to be limited by these terms. These terms are used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section.

2 12 shows an overall configuration of a gas engine 500 according to an embodiment of the present disclosure.

The gas engine 500 includes an engine combustion unit 520 that defines a location where air and fuel are combusted, a supply pipe 510 that corresponds to a duct that supplies air and fuel to the engine combustion unit 520, an exhaust pipe 530 that communicates with the engine combustion unit 520, and corresponds to a duct for discharging exhaust gas generated from the combustion, and a cooling water pipe 550 for cooling the exhaust gas discharged through the exhaust pipe 530 .

The engine combustion unit 520 includes a plurality of combustion chambers. In one embodiment of the present disclosure, an even number of combustors are included. However, the present disclosure is not limited to this. There may be an odd number of combustion chambers. The combustion chamber comprises a housing 521 (see 3 ) that defines an appearance, and a spark plug 523 (see 3 ) to combust air and fuel in the housing 521.

The air and fuel introduced into the case 521 cause an explosive reaction via the ignition (discharge) of the spark plug 523 provided in the case 521 . As a result of the explosion reaction, a cylinder 522 (see 3 ) provided in the housing 521 are subjected to linear reciprocation. Kinetic energy due to reciprocation of the cylinder rotates a crank 526 (see Fig 3 ). The rotation of the crank 526 is transmitted to a rotary shaft (not shown) connected to a compressor to drive the compressor. That is, the rotation of the rotating shaft corresponds to a power source for operating the compressor. The exhaust gas, which is a by-product of the explosion reaction, is discharged into the exhaust pipe 530, and the exhaust gas exchanges heat with the cooling water.

In general, a plurality of combustors have the explosion reaction sequentially at a predetermined interval. That is, the spark plugs 523 provided in the combustion chambers can be successively discharged at a predetermined interval.

The air and fuel intended to enter the engine combustion unit 520 are mixed together in a user-defined mixture ratio prior to entering the engine combustion unit 520 . The air is introduced into the gas engine 500 through an air cleaner 501 and the fuel is introduced into the gas engine 500 through a null regulator 502 . The air and fuel thus introduced are mixed in the mixture 503 and then introduced through an ETC (Electronic Throttle Control) valve 504 into the delivery pipe 510 .

The air cleaning device 501 is configured to filter foreign matter from air so that the explosion efficiency within the engine combustion unit 520 can be maximized. The zero regulator 502 keeps the outlet pressure constant at all times, regardless of changes in the pressure and flow rate of the incoming fuel (gas). The mixture 503 serves to keep the mixing ratio between the air introduced from the air cleaner 501 and the fuel (gas) introduced from the null regulator 502 constant. Thus, controlling so that the mixing ratio between air and fuel gas is constant can enable control of the combustion temperature to be facilitated.

The air and fuel mixed in the mixture 503 at a constant mixing ratio flow into the engine combustion unit 520 via the ETC valve 504 only in the required amount. The ETC valve 504 refers to an electronic control throttle system, which controls the throttle valve electronically. In particular, the ETC valve 504 controls the opening and closing of the throttle valve according to the signal from an electronic accelerator pedal module. Compared to a mechanical throttle valve, the ETC valve can control the opening and closing more precisely.

The air and fuel flowing through the ETC valve 504 flow into the supply line 510 and are then divided into a plurality of branches, and the branched fluids flow into the plurality of housings 521, respectively.

In this process, exhaust gas is generated when the air and the fuel are burned in the plurality of casings 521, respectively. The exhaust gas thus generated is discharged through the exhaust pipe 530, and then flows through the exhaust gas heat exchanger 505 and a muffler 506 in sequence, and then is discharged to the outside.

Meanwhile, the cooling water is absorbed by the cooling water pump 507 and sequentially passes through an exhaust heat exchanger 505, an exhaust manifold 540 and the engine combustion unit 520, and then is discharged to the radiator.

3 12 is a view showing a detailed structure of a combustion chamber of one of engine combustion chambers 520. FIG.

The supply pipe 510 includes a temperature sensor 513 for measuring air temperature and a pressure sensor 514 for measuring a pressure of a mixture of air and fuel.

If the temperature of the air entering the supply tube 510 is too high, the likelihood of incomplete combustion in the combustor increases. Therefore, after the temperature of the inflowing air is measured using the temperature sensor 513 and if the measured temperature is above the predetermined temperature, a separate device is activated to stop the operation in the engine combustion chamber 520 or to cool the temperature of the inflowing air.

A ratio of the incompletely burned gas relative to the whole of the mixture changes depending on a pressure of the mixture of air and fuel. Therefore, the pressure of the mixture is measured using a pressure sensor 514 before the mixture is introduced into the housing 521 to adjust the pressure to the specified optimum pressure. Thus, it is possible to determine whether to increase or decrease the pressure of the mixture based on the value measured by the pressure sensor 514 .

In one example, housing 521 may include a cylinder position sensor 521a for determining the position of the cylinder and a crankshaft position sensor 521c for determining how much crank 526 has rotated.

The crank 526 is connected through the cylinder 522 via a connecting rod 527 . One end of the connecting rod 527 is rotatably connected to a shaft passing through the center of the cylinder 522, while the other end thereof is connected to the crank 526 and rotatably connected to the crank 526 to rotate from a central axis of rotation of the crank 526 in one predetermined distance to be spaced.

Therefore, as the crank 526 rotates, the position of the connecting rod 527 changes continuously. The cylinder 522 is provided within the cylinder housing 528 such that its movement is limited to linear movement only. The cylinder case 528 is provided within the case 521 and communicates with a distal end of the supply pipe 510 and a distal end of the exhaust pipe 530 Spark plug 523 within cylinder housing 528 is ignited. The exhaust gas resulting from the ignition may be discharged to the outside through the exhaust pipe 530 .

A side surface of the cylinder 522 is brought into close contact with the cylinder housing 528 so that the cylinder 522 can move linearly within the cylinder housing 528 . The side surface of the cylinder 522 may be coated with special materials so that air and fuel do not leak between the surfaces of the cylinder 52 and the cylinder housing 528 and friction between the surfaces of the cylinder 52 and the cylinder housing 528 does not occur. In one example, cylinder 52 and cylinder housing 528 can be made of a special material so that little friction can occur therebetween.

As the crank 526 rotates, the cylinder 522 reciprocates linearly due to a change in the position of the connecting rod 527 .

A point at which the supply line 510 and the cylinder housing 528 communicate with each other is controlled by an inflow valve 524 . A point where the exhaust pipe 530 and the cylinder housing 528 communicate with each other is controlled by an exhaust valve 525 .

When the air and fuel mixture is fed into the cylinder housing 528, the inflow valve 524 opens and the outflow valve 525 closes. After the air and fuel mixture enters the cylinder housing 528, the inflow valve 524 is closed.

When both the inflow valve 524 and the outflow valve 525 are closed, the cylinder 522 is furthest from the crank 526 . That is, the mixture of air and fuel introduced into the cylinder body 528 is compressed as much as possible. At this time, the engine is controlled so that discharge is generated in the spark plug 523.

The discharge of the spark plug 523 causes an explosive reaction of the air and fuel mixture introduced into the cylinder body 528 . Thus, the cylinder 522 is pushed out by an explosive force resulting from this explosive reaction. That is, the cylinder 522 moves up and down due to the explosive force, and thus the crank 526 is rotated due to the reciprocating linear motion of the cylinder 522 . Rotation of the crank 526 may allow the rotary shaft connected to the crank 526 to rotate to operate the compressor.

The exhaust valve 525 is opened after discharge to discharge the exhaust gas generated by the discharge of the spark plug 523 . The exhaust gas is discharged to an exhaust pipe 530 through the exhaust valve 525 .

When the exhaust gas has been expelled, the discharge valve 525 is closed again and the inflow valve 524 is opened to allow fresh air and fuel mixture to flow there. Such an operating cycle may last as long as the combustion chamber 520 of the engine is operating.

The plurality of combustors may be provided. In this regard, the discharges of the spark plugs 523 may occur at different times in at least some of the combustion chambers.

A cooling water temperature sensor 521 b may be further provided in the case 521 . The temperature of the cooling water supplied to the outside of the cylinder housing 528 is measured by the cooling water temperature sensor 521b. If the temperature of the cylinder housing 528 is too high, part of it may wear out. Thus, when the temperature of the cooling water is measured to be higher than a reference temperature, it can be determined that the engine combustion chamber 520 is in a dangerous state, and the operation of the engine combustion chamber 520 can be stopped.

As described above, the explosive power may vary in proportion to the amount of air and fuel flowing into the cylinder housing 528 or the amount of energy released from the spark plug 523 . That is, energy consumption can be minimized and maximum efficiency can be achieved when explosive force is accurately controlled according to a charge required by the compressor connected to engine combustion chamber 520 .

According to an embodiment of the present disclosure, the explosive power of the air and fuel mixture can be controlled by controlling the amount of energy released from the spark plug 523 . After determining a charge of refrigerant required by the compressor, a required output energy may be calculated according to the determined charge, and then the amount of energy output from the spark plug 523 may be adjusted based on the output energy.

The output energy required based on this load can be defined as a target ignition energy amount. To determine the desired amount of ignition energy, the controller may first determine a user specified setpoint. For example, the controller may designate one of heating mode and cooling mode as user-selected, a user-set temperature, and an intensity of airflow as user-selected. The setting values can be determined by a controller 600 that is provided in the gas heat pump. The controller 600 may be embodied as an engine control unit (ECU) 610 to control operation of the engine. In some cases, the controller 600 can be implemented as a separate component that controls the ECU 610 and drives the entire gas heat pump. Hereinafter, an example in which the controller 600 is embodied as the ECU 610 is exemplified. However, the present disclosure is not limited to this. Therefore, the controller 600 and the ECU 610 are described below using the same reference numeral 610. FIG.

Depending on the heating/cooling mode, the set temperature and the intensity of the airflow, the required refrigerant charge may vary. In this regard, a speed of the compressor may vary depending on the required refrigerant charge. The output amount of the gas engine 500 rotating the compressor may be predetermined according to the refrigerant charge determined above. The relationship between the refrigerant charge and the output of the gas engine 500 can be experimentally obtained in advance and stored in the controller 610 in the form of a table in advance.

Once the output of the gas engine 500 is determined, the amount of output energy required by the spark plug 523 can be determined according to that output. That is, the required amount of refrigerant can be determined as user-selected according to the values set by the user, such as cooling / heating mode, temperature or wind intensity. Then, the output amount of the gas engine 500 can be determined according to the determined refrigerant charge. Finally, the amount of output energy required by the spark plug 523 may be determined according to the determined output amount.

This amount of output energy can be controlled by varying a length of dwell time. The longer the dwell time, the greater the amount of current that flows in a primary coil 611 (see 4 ). This is because the coil acts as the inductor. In the inductor, a resistance value gradually decreases with time after voltage is applied thereto. That is, while the value of the resistor gradually decreases over time, the applied voltage is constant. Thus, the amount of current flowing in the inductor may gradually increase over time.

When ignition (discharge) from the spark plug 523 occurs, a period during which the ignition (discharge) is maintained may vary depending on the magnitude of the current supplied to the primary coil 611 . The larger the current, the longer the time during which ignition (discharge) is maintained. The smaller the current, the shorter the time during which ignition (discharge) is maintained.

The magnitude of the amount of output energy is related to a length of time for which ignition (discharge) takes place. This is because the amount of output energy is calculated by integrating a product of the applied voltage and the applied current over time. Therefore, as the dwell time becomes longer, the amount of current flowing in the primary coil 611 gradually increases. The amount of output energy can be larger because the time for which the ignition (discharge) is maintained is lengthened.

In one example, the amount of output energy can be adjusted by varying the magnitude of the applied voltage. As the magnitude of the voltage applied to the primary coil 611 increases, a higher voltage may be generated in the secondary coil 612 .

Furthermore, when the magnitude of the voltage applied to the primary coil 611 increases, the desired amount of current can be obtained even if the dwell time is short. That is, even if the same dwell time is used, the amount of current that is reached may vary according to the magnitude of the voltage initially applied. In order to achieve the same desired amount of current, the greater the applied voltage, the shorter the dwell time.

In summary, the magnitude of the amount of output energy can be controlled by changing the length of the dwell time and the magnitude of the voltage applied to the primary coil 611 .

When the spark plug 523 is controlled using the magnitude of the output energy, there is an advantage that the output of the gas engine 500 can be more accurately controlled according to the refrigerant charge of the compressor.

4 and 5 show a simple circuit for measuring voltage and current.

4 shows a circuit that boosts a low voltage to a high voltage. To ignite the mixture of air and fuel it is possible to raise the voltage to 20000-30000 volts to create a spark. However, a battery attached to the circuit will output a low voltage of 10 to 30 volts.

Electromagnetic induction of a transformer 610 consisting of a coil is used to increase the voltage. The coil constituting the transformer 610 may be, for example, a secondary coil 612 with about 20000 to 30000 turns of a thin copper wire about the thickness of a hair wound around a rod-shaped iron core, and the primary coil 611 with 150 to 300 turns of a copper wire of about 0 .5 to 1 mm thick wound around a bar-shaped iron core in the same direction as the secondary coil.

In this connection, the iron core can act as an electromagnet when the current flows in the primary coil 611 by applying a voltage or when the current flow is interrupted. A current of high voltage may flow through the secondary coil 612 due to an electromagnetic induction phenomenon when the current flowing in the primary coil 611 ends.

A switching element 640 provided in the circuit can flow in the primary coil 611 block current. When the switching element 640 receives an ignition signal from the controller or ECU 610 , the switching element 640 can block the current flowing in the primary coil 611 so that a high voltage is induced in the secondary coil 612 . In this regard, the switching element 640 may use a power transistor, for example an insulated gate bipolar transistor (IGBT).

A part that includes the primary coil 611 and allows or does not allow current to flow in the primary coil 611 may be referred to as an ignition coil part 601 . A part including the secondary coil 612 and the spark plug 523 can be defined as a spark plug part 602 .

The operation of the spark plug 523 is not limited to this. The scheme described above corresponds to an all-transistor ignition scheme. Spot ignition or distributorless ignition schemes can be used.

5 10 shows a circuit structure capable of measuring current according to an embodiment of the present disclosure.

The current measurement is made by measuring the current flowing through a shunt resistor 631, which has a very small resistance. At this time, the current measuring unit 630 measures the current flowing through the shunt resistor 631 . A voltage is measured via a voltage measurement unit 620 . The amount of energy applied to the spark plug 523 can be calculated in advance by providing the circuit capable of measuring the voltage and current in advance.

6 12 shows a voltage applied to each of four combustors in combustor 520 according to an embodiment of the present disclosure. Referring to 6 shows the change in voltage applied to the primary coil 611 in each combustion chamber. The spark plugs 523 in the combustion chambers can sequentially perform ignition.

The voltage corresponding to the capacity of the battery can be constantly applied to the spark plug 523 before ignition occurs. If the switching element 640 blocks the current supplied to the primary coil 611 after receiving the signal from the controller 610 , a high voltage may be generated in the secondary coil 612 .

The dwell time may be present to control the amount of current supplied to the primary coil 611 . This dwell time corresponds to one lower period of a pulse (indicated by a bidirectional arrow) in 6 . After the dwell time, the switching element 640 interrupts the current supplied to the primary coil 611 so that a high voltage is generated in the secondary coil 612 . This may cause ignition (discharge) from the spark plug 523.

7 FIG. 12 is a simplified flowchart depicting operation in accordance with the present disclosure.

According to an embodiment of the present disclosure, since the intensity of ignition is controlled based on the amount of energy generated when ignition (discharge) occurs in spark plug 523, measurement of voltage and current may be required.

Therefore, a step S100 may be required in which a circuit for measuring the voltage applied to the primary coil 611 and the current flowing therein for each cylinder 522 is prepared.

The gas engine 500 can be activated using the circuit that can measure the voltage and current (S200).

When the gas engine 500 is activated, the ignition coil voltage applied to the primary coil 611 and the current flowing therein can be measured in real time by the controller 610 at S300. This can be done in real time to determine whether the target ignition energy amount is being met each time ignition (discharge) from a single spark plug 523 occurs. Then, the actual output energy amount can be calculated based on the measured information and can be considered in a next ignition.

Subsequently, a process S400 for performing optimal control of the gas engine 500 based on the measured information may be performed.

As described above, the process S400 for performing control of the gas engine 500 based on the measured information according to an embodiment of the present disclosure using a flowchart is shown in FIG 8th shown in detail.

In one example, the cooling mode or heating mode, temperature setting, and/or airflow intensity may be determined by the controller 610 as being set or selected by the user or via an automated system. That is, the heating/cooling operation state (heating/cooling cycle) can be set in S410.

The controller 610 can receive the above setting conditions from outside. Thus, the operating states may include at least one of cooling and heating mode setting, temperature setting, and airflow intensity setting.

Specifically, in step S411, the controller 610 may set a heating/cooling cycle condition.

Once the cool/heat mode has been set, the controller 610 determines the required refrigerant charge according to the set condition. That is, the controller 610 can determine the load based on the cooling/heating and the cycling state. This determination can be made in real time. Alternatively, the load can be determined from the table stored in the controller 610 based on the cooling/heating and cycle state.

The controller 610 then sets the target ignition energy amount according to the required refrigerant charge (S413). This target amount of ignition energy may be set by the controller 610 . Alternatively, the desired ignition energy amount may be determined based on the refrigerant charge using the pre-stored table.

When the target ignition energy amount is set as described above, the controller 610 may control the spark plug 523 in the combustion chamber to generate ignition (discharge) once at S420.

In this case, the actual amount of output energy can be calculated by measuring the magnitude of the supplied current that changes according to the voltage applied to the primary coil 611 and the dwell time during one-time ignition discharge. The controller 610 can perform this calculation.

Once the actual amount of energy output has been calculated, the controller 610 may determine whether the desired amount of ignition energy and the amount of energy output are equal and vary the ignition state based on the determination.

Specifically, when the actual output energy amount has been calculated, the controller 610 may compare the target ignition energy amount and the output energy amount and determine whether they are equal to each other in step S431.

In this regard, the controller 610 may correct the amount of energy required for ignition when the target amount of ignition energy and the amount of output energy differ from each other. In one example, the controller 610 may correct the dwell time in step S432.

For example, when the output energy amount is less than the target ignition energy amount, the controller may increase the dwell time before ignition in a next ignition time. When the dwell time has been increased, the magnitude of the current supplied to the primary coil 611 before ignition (discharge) is increased, and the time for which ignition (discharge) lasts can be further increased. Therefore, the amount of output energy in the next ignition (discharge) becomes large.

In contrast, when the output energy amount is larger than the ignition energy amount, the residence time in the next ignition can be reduced. When the dwell time has been reduced, the magnitude of the current supplied to the primary coil 611 before ignition (discharge) is reduced, and the time for which ignition (discharge) is maintained can be further reduced. Therefore, the amount of output energy in the next ignition (discharge) can be reduced.

In one example, although in 8th not shown, a process for correcting the amount of energy required for ignition can be adjusted by varying the magnitude of the voltage applied to the primary coil 611.

If the voltage magnitude is decreased while the dwell time is being set, the magnitude of the current supplied to the primary coil 611 may decrease before ignition (discharge) occurs. Accordingly, the time for which ignition discharge is maintained can be further reduced.

Thus, when the output energy amount is larger than the target ignition energy amount, the magnitude of the voltage applied to the primary coil 611 in the next ignition can be reduced. When the output energy amount is smaller than the target ignition energy amount, the magnitude of the voltage applied to the primary coil 611 in the next ignition can be increased.

Since a final criterion is the amount of energy output, the dwell time and/or the magnitude of the voltage can be changed depending on the situation to change the amount of energy output.

In one example, if the output energy amount and the target ignition energy amount are equal, the controller can determine whether the cooling/heating condition, temperature setting, and air flow intensity setting has been changed by the user or the system. That is, the controller can determine whether a new operating state is set (S440).

In this regard, the required refrigerant charge varies when the setting is changed or when the new operating condition is established. Thus, when the refrigerant charge is changed, the target ignition energy amount can be changed. If the settings change slightly, the controller may need to follow the steps above.

In this regard, when the setting is changed or when the new operating condition is set, the refrigerant charge determination step S412 may be re-executed based on the changed setting condition. If the required target ignition energy amount is then reset based on the changed required refrigerant charge, a new ignition (discharge) from the spark plug 523 may occur.

In one example, if there is no new setting change, the controller may determine whether or not the engine is still running (S450).

In this regard, when the engine stops running, since ignition (discharge) is not required, the spark plug does not perform ignition (S460).

In contrast, if the engine continues to run, the process may return to step S420, where re-ignition (discharge) from the spark plug 523 may occur. Unless the new setting change occurs or the engine continues to run, the controller may continually determine whether the output energy amount and the desired ignition energy amount are equal each time ignition (discharge) occurs. When it is determined that the output energy amount and the target ignition energy amount are equal, the dwell time can be corrected or the magnitude of the applied voltage can be corrected.

As described above, since the controller 610 can determine and correct the output energy amount every occurrence of ignition from the spark plug 523, the energy efficiency can be greatly improved compared to the conventional one. Since the controller receives the feedback based on the amount of energy, the controller can more accurately control the ignition (discharge) compared to the conventional method.

The embodiments of the present disclosure, as disclosed herein and in the drawings, merely illustrate specific examples for purposes of understanding. The scope of the present disclosure should not be limited to the embodiments. It is obvious to those skilled in the art that other changes based on the technical idea of the present disclosure are possible in addition to the embodiments disclosed herein.

Industrial Applicability

According to the present disclosure, the engine controller has the effect of varying the dwell time according to the amount of ignition energy output from the spark plug and achieving precise control.

Claims (13)

A method for controlling a gas heat pump having a compressor for compressing refrigerant and a gas engine for driving the compressor, the gas engine comprising: an engine combustion unit having a plurality of combustion chambers and a spark plug arranged at each of the engine combustion chambers for combusting a mixture of air and fuel, the method comprising: determining a refrigerant load based on a cooling or heating mode or a temperature setting (S412); determining an output amount of the gas engine based on the determined refrigerant load (S412); setting a target ignition energy amount (S413) required by the spark plug based on the output amount; igniting the spark plug in each combustion chamber (S420); measuring a magnitude of a current that changes based on a voltage applied to the spark plug and based on a dwell time of the spark plug in real time for each ignition timing; comparing an actual amount of output energy generated by the ignition with the set target amount of ignition energy (S431); and changing an amount of energy required to ignite the fuel when the output energy amount and the target ignition energy amount are not equal (S432); and determining whether the operating state has changed when the output energy amount is equal to the target ignition energy amount (S440), wherein if the operating state has changed, setting the target ignition energy amount comprises setting a new refrigerant charge and a new target ignition energy amount (S412, S413). procedure after claim 1 , wherein changing the amount of energy required to ignite the fuel includes changing a dwell time (S432). procedure after claim 2 , where when the output energy amount is greater than the target ignition energy amount, the dwell time decreases. procedure after claim 2 , where when the output energy amount is less than the target ignition energy amount, the dwell time increases. procedure after claim 1 , wherein changing the amount of energy required to ignite the fuel includes adjusting a voltage applied to the spark plug (S432). procedure after claim 5 , wherein when the output energy amount is larger than the target ignition energy amount, a magnitude of the voltage decreases. procedure after claim 5 , wherein when the output energy amount is smaller than the target ignition energy amount, a magnitude of the voltage increases. procedure after claim 1 , further comprising, if the operating condition has not changed, determining whether the gas engine is currently running (S450). procedure after claim 9 , when the gas engine is currently stopped, the ignition ends (S460). procedure after claim 1 , wherein both the output energy amount and the target ignition energy amount are calculated by integrating a product of a voltage applied to the spark plug and a current over the ignition period. Gas heat pump comprising: a compressor for compressing refrigerant; a gas engine (500) for driving the compressor, the gas engine (500) including an engine combustion unit (520) having a plurality of combustion chambers; a spark plug (523) disposed at each of the engine combustion chambers, the spark plug (523) applying a surge voltage; and a controller (600, 610) for controlling a voltage and current applied to the spark plug (523) and a discharge time of the spark plug (523), wherein the controller (600, 610) is configured to: determining a refrigerant charge based on a cooling or heating mode or a temperature setting; setting a target amount of ignition energy required by the spark plug based on the output amount; measuring a magnitude of a current that changes based on a voltage applied to the spark plug (523) and based on a dwell time of the spark plug (523) in real time for each ignition timing; comparing an actual output energy amount generated by discharge of the spark plug (523) with the target ignition energy amount; and changing an amount of energy required to ignite the fuel when the output energy amount and the target ignition energy amount are not equal; and determining whether the operating state has changed when the output energy amount is equal to the target ignition energy amount, wherein if the operating condition has changed, setting the desired amount of ignition energy comprises setting a new refrigerant charge and a new desired amount of ignition energy. gas heat pump claim 11 , wherein the controller (600, 610) is arranged to change a dwell time when the output energy amount and the target ignition energy amount are not equal. gas heat pump claim 11 , wherein the controller (600, 610) is arranged to change a magnitude of a voltage applied to the spark plug (523) when the output energy amount and the target ignition energy amount are not equal.

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